Most soldiers are afraid of battle, even if they pretend they are not.
One of the main themes of the book is that everyone is afraid. Courage does not mean not being afraid; it means working against your fear, and keeping on when you are scared.
Henry is aware that the men who seem so ready to fight are also afraid, even though he wonders if he is the only one.
His emotions made him feel strange in the presence of men who talked excitedly of a prospective battle as of a drama they were about to witness, with nothing but eagerness and curiosity apparent in their faces. It was often that he suspected them to be liars …(ch 2)
For a soldier to not be afraid, he would have to have a death wish. All soldiers face danger. They may get a thrill from facing death, but part of that thrill comes from fear of death.
War is not romantic. It is certainly not pleasant. Soldiers are afraid, but they are brave. Henry was constantly worried that someone would realize that he was afraid, but he did not understand that everyone else around him was too.